It was in Southern England in a place called Cheddar that it was found that the natural carotene color in milk was carried through to the cheese curd in high levels during the summer month when the cows were feeding on fresh grass and in lower levels during fall and winter when the cows were fed hay. Thus, the natural color of cheese varied over the course of a year and the visual aspect of the color became important in terms of consumer perception of the quality of cheddar cheese.
Cheese makers then started to add coloring agents. Traditionally, the most common of these is annatto, a yellow-red dye made from the seeds of the Bixa orellana tree (Carrie, 1938). The pigments of annatto are two carotenoids; the fat soluble part of the crude extract is called bixin the water-soluble part is called norbixin.
Dyeing the cheeses eliminates seasonal color fluctuations and the use of annatto color is extremely important to achieve the visual appearance of colored cheese, including cheddar, Leicester, Gloucester, etc.
The whey obtained during the cheese process contains significant level of proteins, and in order to be able to valorize this protein, various harsh chemical treatments have been suggested (McDonough et al., 1968), and these all impose undesirable traits for the whey protein, e.g. oxidized flavor, impaired nutritional value and generation of unwanted yellowish color due to oxidation products (Croissant et al., 2009).
A number of carotenoids are found naturally in cows milk, i.e. lutein, violaxanthin, antheraxanthin, zeaxanthin, neoxanthin, all-trans beta-carotene, alpha-carotene, and 13-cis beta-carotene, and among those, lutein and beta-carotene are the most abundant quantitatively (Noziere et al., 2006).
An overall trend within food products is a wish for the products to contain ingredients which are already in the products in nature. Because of the consumer preferences and issues regarding quality or utility of the whey fraction following use of annatto as colorant (Kang et al., 2010), the use of carotenoids, and especially beta-carotene, to color food, particularly cheese, has been researched (Lück and Downes, 1972; Luck, 1973; Chapman et al., 1980).
Beta-carotene is a useful cheese coloring agent because it is naturally present in milk, it gives cheese a color which appeals to the customer and it does not produce off-flavors during the ripening of the cheese.
The use of beta-carotene to color cheese is advantageous over annatto in that the chemical compound may be more closely controlled than the natural product. Beta-carotene may be synthesized or extracted from natural sources. Additionally, discovered health benefits of beta-carotene further promote the use of the substance over annatto.
Processing of some milk products (e.g. cheese and butter) involves selective transfer of constituents from milk to milk products. Given that carotenoids and retinol are fat-soluble, they mainly behave like milk fat (Noziere et al., 2006).
However, beta-carotene, and especially annatto, preparations face the problem that a large amount of color is lost in the whey during the cheese making process.
GB 2248170 uses emulsified beta-carotene with caseinate as ingredient thereby claiming that the beta-carotene is better trapped in the cheese curd and not transferred to the whey fraction.
WO 99/07233 relates to producing a uniform coloration in cheese by associating a food grade colorant, such as beta-carotene, with a carrier, such as caseinate, which is then dispersed within the milk source that is processed into a final cheese product.
US 2001/0046546 relates to a mixture of synthetic carotenal (carotenoid containing an aldehyde functional group) and natural beta-carotene in butter oil (anhydrous milk fat), as a carrier, for use as a colorant in food products, such as processed cheese.
Other patent documents are related to increasing the carotenoid concentration by using a hydrocolloid as a carrier or matrix.
WO 2007/009601 is directed to a composition comprising at least one carotenoid, such as beta-carotene, which is dispersed in a matrix containing at least one starch and/or modified starch.
WO 2008/110225 relates to compositions comprising gum acacia and at least one carotenoid for coloration of food, beverages, animal feed, cosmetics or pharmaceutical compositions.
WO 2010/112406 is directed to a stable suspension of partially amorphous carotenoid particles, comprising 1 to 20% (w/w) of at least one carotenoid, such as beta-carotene, 0.2% (w/w) to 20% (w/w) of an edible oil, 3% (w/w) to 60% (w/w) of a hydrophilic protective colloid, 5% (w/w) to 60% (w/w) of a physiologically suitable polyalcohol and 5% (w/w) to 60% (w/w) of water.
Nevertheless, an attempt to match the color shade of annatto, norbixin, using beta-carotene for certain cheddar cheeses has not been successful, and authors state that final color shade using beta-carotene is too yellow compared to that of annatto (Chapman et al., 1980).
Therefore, paprika has been used in combination with beta-carotene to provide a finished cheese product with the same color as annatto-colored cheeses.
WO 2010/069889 relates to a composition for coloring cheese curd comprising a combination of an oil phase comprising an effective amount of paprika, an effective amount of a carotenoid, and a fat, and an aqueous phase comprising a caseinate.
Thus, there is a need for alternative and improved beta-carotene coloring compositions that prevents coloration of the whey by-product stream, while simultaneously providing a finished cheese product with the same color as annatto-colored cheese.